Electron loss from helium atoms by collisions with fully stripped ions

Electron-loss cross sections have been calculated for fully stripped ions with charge states +1 to +100 colliding with helium atoms in the energy range 100--1000 kev/amu. The classical-trajectory Monte Carlo method was used along with a model of the helium atom with two active electrons. The reactions studied were single and double ionization, single- and double-electron capture, and electron capture plus ionization. Cross sections for the single-electron-removal reactions agree well with experimental data. Double-electron-removal cross sections are in qualitative agreement with experimental results. The n-level distributions following electron capture show that the electron-capture--plus--ionization and double--electron-capture processes are peaked at a lower n level relative to single-electron capture.